In recent years, for the purpose of environmental conservation or the like, a vehicle which drives using electric energy as a driving power source (which, hereinafter, will be simply referred to as an electric vehicle) has been developed. The electric vehicle incorporates many electric components such as batteries for storing DC power, an inverter for converting the DC power stored in the batteries into AC power, and an electric motor activated by the output of the inverter. These electric components operate in association with each other. For example, Patent Literature 1 discloses that an abnormality in an electric component is diagnosed based on an electric characteristic of the electric component.